Johnson & Johnson and Crucell have announced this morning that they are in advanced negotiations over a deal which would see the US healthcare giant buy the near-82% stake in the Dutch vaccines group it does not already hold.

Under the terms of the proposed transaction, J&J, which holds 17.9% of Crucell's shares, will pay 1.75 billion euros in cash, or 24.75 euros per share, to take control of the business. That represents a 58% premium on the Leiden-headquartered firm's closing price on Thursday.

After the deal closes, and analysts believe there is little chance of any rival bids coming in, J&J says it expects to keep Crucell's existing facilities, retain senior management and "generally to maintain current employment levels". It would also "retain its entrepreneurial culture that has fostered innovation and growth".

Crucell's business is looking pretty healthy and for the second quarter it posted total revenues and other operating income of 128.6 million euros, a 63% rise and driven by the paediatric vaccine Quinvaxem. Net profit was 9.2 million euros, compared with a loss of 1.8 million euros in the like year-earlier period.

Crucell has attracted the interest of other suitors in the past and in January 2009 "friendly" takeover talks were held with Wyeth, which was subsequently bought by Pfizer. Then J&J bought its stake in September of last year.

Although the New Jersey-based behemoth says that due diligence is "substantially complete, the transaction remains subject to negotiation of terms of a definitive agreement". The proposed deal has gone down well with analysts and especially with investors - at 9.50am this morning (UK time), Crucell's shares were up over 54% to 24.20 euros.